103results about "Azeotropic/extractive distillation" patented technology

A process is disclosed for generating pure aromatic compounds from a reformed gasoline which contains aromatic compounds, olefins, diolefin, and triolefins, which comprises the steps of: (a) selectively hydrogenating the olefins, diolefins and triolefins in the reformed gasoline to obtain a mixture of hydrogenated, non-aromatic compounds and aromatic compounds; and (b) separating the aromatic compounds from the hydrogenated, non-aromatic compounds in the mixture formed during step (a) by either extractive distillation, liquid-liquid extraction or both to obtain the pure aromatic compounds.

A process for increasing the production of benzene from a hydrocarbon mixture. A process for producing an aromatic hydrocarbon mixture and liquefied petroleum gas (LPG) from a hydrocarbon mixture, and a solvent extraction process for separating and recovering polar hydrocarbons from a hydrocarbon mixture containing polar hydrocarbons (that is, aromatic hydrocarbons) and nonpolar hydrocarbons (that is, non-aromatic hydrocarbons) are integrated, thereby it is possible to increase the production of benzene.

Extractive distillation processes whereby water-soluble extractive distillation (ED) solvents are regenerated and recovered employ improved operations of the extractive distillation column (EDC) so that polar hydrocarbons are recovered and purified from mixtures containing polar and less polar hydrocarbons and measurable amounts of hydrocarbons that are heavier than intended feedstock and/or polymers that are generated in the ED process. The improved process can effectively remove and recover the heavy hydrocarbons and/or remove polymer contaminants from the solvent in a closed solvent circulating loop through mild operating conditions with no additional process energy being expended. With the improved process, the overhead reflux of the EDC may be eliminated to further reduce energy consumption and to enhance the loading and performance within the upper portion of the EDC, especially when two liquid phases exists therein.

This application relates to a composite solvent for separating aromatics by extractive distillation, comprising a main solvent, a solutizer and a modifier. Said solutizer is selected from any one or mixtures of any two of C₈–C₁₁ aromatics having different number of carbon atoms, the content of which is 3–39 wt %, and the number of carbon atoms of the lowest aromatic in the solutizer should be greater than that of the highest aromatic in the aromatics to be separated. When the solutizer is selected from any one of C₈–C₁₁ aromatics, the composite solvent contains 0.01–10.0 wt % of the modifier; when the solutizer is selected from mixtures of any two of C₈–C₁₁ aromatics having different number of carbon atoms, the composite solvent contains 0–10.0 wt % of the modifier. Said main solvent and modifier are independently selected from sulfolane derivatives, N-formyl morpholine, and N-methyl pyrrolidone, provided that the acidity and basicity of the modifier are opposite to those of the main solvent. When the composite solvent is used to recover aromatics by extractive distillation, it is possible to moderate the operation conditions of solvent recovery, increase the yield of aromatics, and make the separated aromatics to be neutral.

A top temperature T₁ of a distillation tower 1 is held below a liquefying temperature of a light fraction by returning a part of an exhaust gas W, which is cooled by a condenser 5, to the upper zone of the distillation tower 1. A bottom temperature T₂ is raised up to 300° C. at highest by returning a part of a liquid product P from a re-boiler 3 to a lower zone of the distillation tower 1. When a liquid hydrocarbon L comes in countercurrent contact with a stripping gas G inside the distillation tower 1 with the temperature profile that an inner temperature gradually falls down along an upward direction, mercury is efficiently transferred from the liquid L to a vapor phase without effusion of the light fraction in accompaniment with the exhaust gas W.

The invention is a process for preparing lower olefins comprising: a) steam cracking a paraffinic feedstock to obtain a cracker effluent comprising olefins and saturated and unsaturated C4 hydrocarbons; b) contacting an oxygenate feedstock with a molecular sieve-comprising catalyst, at a temperature in the range of from 350 to 1000° C. to obtain an oxygenate conversion effluent comprising olefins and saturated and unsaturated C4 hydrocarbons; c) subjecting the cracker effluent and the oxygenate conversion effluent to one or more separation steps such that an olefin product stream comprising ethylene and/or propylene, and a stream comprising saturated and unsaturated C4 hydrocarbons are obtained; and d) subjecting part of the stream comprising C4 hydrocarbons from both the cracker effluent and the oxygenate conversion effluent to extractive distillation to obtain a stream enriched in unsaturated C4 hydrocarbons and a stream enriched in saturated C4 hydrocarbons.

It is described a prefractionation-physical absorption hybrid process and system for separation of a CO₂-natural gas mixture containing more than 26 mol % CO₂ and 0.1 mol % to 15 mol % in total one or more heavier hydrocarbons, such as ethane, propane, butanes, pentanes, and hexanes, with at least 0.0001 mol % in total one or more of pentanes and hexanes, particularly, a self-refrigerated process and system involving methanol as the absorbent.

An extractive distillation process for separating at least one substituted unsaturated aromatic from a pyrolysis gasoline mixture, containing said aromatic and at least one close-boiling aromatic or non-aromatic hydrocarbon, employing a two part extractive solvent: (a) sulfolane (tetramethylene sulfone), and (b) portion consisting of water.

The present invention relates to a process for recovering polar hydrocarbons from non-polar hydrocarbons, such as aromatics from non-aromatics, naphthenes from paraffins and isoparaffins, or olefins from paraffins and isoparaffins, in feed mixtures containing at least a measurable amount of heavier hydrocarbons. According to the invention, an improved extractive distillation (extractive-distillation) process is disclosed for recovering aromatic hydrocarbons including benzene, toluene, and xylenes from heavy (C₉+) hydrocarbons. The invention also relates to an improved extractive-distillation process for recovering mainly benzene and toluene from the C₆-C₇ petroleum streams containing at least a measurable amount of C₈+ hydrocarbons. This invention is further directed toward the regeneration and recovery of the extractive-distillation solvent utilized to recover and purify the aromatic hydrocarbons from the petroleum stream containing at least a measurable amount of hydrocarbons heavier than the intended product.

The invention relates to a method for extracting phenol compounds from direct coal liquefied oil through extractive distillation. An extractive distillation solvent (hereinafter referred to as solvent) adopted in the method is glyceryl triacetate and/or sulfolane, or a mixed solvent formed by mixing glyceryl triacetate and/or sulfolane and one or more selected from glycerol, triethanolamine, triethylene glycol, tetraethylene glycol, dimethyl sulfoxide and diethanol amine according to any proportion. The method is used for extracting phenol compounds from direct coal liquefied oil in an extraction distillation tower by using the solvent, then, a solvent flow rich in the phenol compounds enters a recovery tower and is separated, the phenol compounds discharged from the top of the recovery tower are recovered after being cooled to obtain phenol products, and the solvent is recycled after being discharged from the bottom of the recovery tower. The method has the characteristics of high product purity, low system energy consumption, no wastewater generation, no acid and alkaline waste and no corrosion to equipment.

A method for recovering waste iron-base catalyst and heavy hydrocarbon includes extracting and separating mixer of waste iron-base catalyst and heavy hydrocarbon with high liquid paraffin having initial distillation point of 210 deg.C for three to four times for achieving purpose of separating catalyst from heavy hydrocarbon. The recovered waste iron-base catalyst is to be buried underground and the recovered mixer of light liquid paraffin and heavy hydrocarbon can be directly used to produce oil product or sent back to fluid bed reactor for being reutilized as reaction media.

A method for recovering cobalt-base catalyst and heavy hydrocarbon includes extracting and separating mixer of waste cobalt-base catalyst and heavy hydrocarbon with liquid paraffin having initial distillation point of 210 deg.C for three to four times, using dimethylbenzene to extract and separate for two to three times. The recovered mixer of liquid paraffin and heavy hydrocarbon can be used as reaction media in fluid bed reactor and the recovered waste cobalt-base catalyst can be directly used to recover valuable metal of cobalt.

Recovering a polar hydrocarbon (HC) selective solvent substantially free of hydrocarbons (HCs) and other impurities from a lean solvent stream containing the selective solvent, measurable amounts of heavy aromatic HCs, and polymeric materials that are generated in an extractive distillation (ED) or liquid-liquid extraction (LLE) process. At least a portion of the lean solvent stream is contact in a solvent clean-up zone with a slip stream from the HC feed stream of the ED or LLE process or an external stream. The HC feed stream, such as pyrolysis gasoline or reformate, contains significant amounts of benzene and at least 50% polar (aromatic) HCs and serves as a displacement agent to remove the heavy HCs and polymeric material from the lean solvent stream. A magnetic filter can be used to remove the paramagnetic contaminants from the lean solvent.

Crude containing a comparatively large content of nickel, vanadium, or carbon residue is treated so as to supply a raw material to a downstream catalytic cracking process, A primary distillation tower fractionates first crude into a residue fraction partly used as raw oil of a catalytic cracking process and other fractions. A secondary distillation tower fractionates second crude containing a larger content of a catalytic poison with respect to catalysts used in the catalytic cracking process than the first crude into a light fraction included in a distillation temperature range of the other fractions and a heavy fraction as a rest thereof. A light fraction supply line supplies the light fraction to the primary distillation tower so as to be treated in the primary distillation tower.

The invention discloses a device and a method for separating olefin from Fischer-Tropsch synthetic oil. The device combines a partition wall tower and an extractive rectification technology, a partition plate is arranged in the partition wall tower, the partition wall tower is divided into an extractive fraction part, a rectification part and a public stripping part, and the extractive fraction part is used for extracting alkane; the side line rectification section is used for extracting olefin, and the public stripping section is used for extracting the mixture of oxygen-containing compound and extractant, thereby realizing the purpose that alkane, olefin and oxygen-containing compound can be simultaneously separated from the cut Fischer-Tropsch synthetic oil in a partition tower, and caneffectively reduce the problems of high equipment cost and high operation cost when olefin is separated from the Fischer-Tropsch synthetic oil fraction, thereby improving the economic benefit of theoil product.

A split-shell column includes a raffinate column portion for separating a raffinate material from a desorbent material and a desorbent rerun column portion for separating heavy contaminants from the desorbent material. A feed to the desorbent rerun column portion is provided from the desorbent material in the raffinate column. The desorbent rerun column portion occupies a portion of a lower end of the split-shell column and is thermally separated from the raffinate column portion.

The invention relates to the field of refining of hydrocarbon materials, and discloses a method for deeply desulfurizing a sulfur-containing raw material. The method is characterized in that solvent extraction of the sulfur-containing raw material and an extracting solvent is carried out through distillation to obtain a sulfur-containing solvent and a desulfurized product, wherein the extracting solvent contains a main extracting solvent and an assistant, the assistant is at least one substance of alcohols, ketones, organic acids and organic nitrides being intermiscible with the main extracting solvent and having a boiling point or a dry point being not more than the boiling point or the dry point of the main extracting solvent and/or water, and the organic nitrides are at least one of amines, carbamides and hydramines. The method can deeply remove sulfides from the sulfur-containing raw material, such as gasoline even under a hydrogen source-free or hydrogen source-deficient condition, and achieves basic no loss of the octane number.